This invention relates to hard surface cleaning compositions. More particularly, it relates to compositions useful for removing burned-on food or other organic deposits from hard surfaces of, for example, ovens, pots, and pans. Such a composition contains primarily an aqueous solution of an alkaline material and a water insoluble, fibrous polymer, the latter of which is capable of absorbing a large volume of liquid.
When used in cooking, pots and pans are liable to soiling by burned-on organic deposits of natural fats, oils, and other residues of cooked food. When heated at normal cooking temperatures, these deposits are converted into a hard, infusible polymeric mass in which part of the deposits may be charred. Detergents scouring powders and similar cleaning products, such as dishwashing liquid products, are not adequate for removing these deposits because of their generally inpenetrable nature.
The removal of this type of soil is therefore a considerable problem, requiring generally powerful chemical or physical action. Among the most effective chemical compounds known for this purpose are the caustic alkalis, such as sodium or potassium hydroxide. They may be applied to the stained utensil directly by brush, sponge, or more conveniently by means of an aerosol spray. Products of this type, although efficient in their action, suffer from a number of disadvantages. One disadvantage is that such products when applied to soiled utensils attack the soiling matter from its outer layer, while the most severe charring and polymerization is generally present in the interior of the matter adjacent the utensil's surface. This makes removal more difficult. Second, because of the nature of the caustic alkalis and of conventional cleaning compositions having a high concentration of caustic alkali, it has been known to be necessary to employ considerable safety measures in their use. However, alkalis less alkaline than caustic alkali have not previously been found to be effective in hydrolyzing burned-on deposits in a reasonable time of application. Thus, the problem which existed prior to the invention of the compositions herein was that a cleaning composition was needed which could penetrate a burned-on deposit to effect its prompt removal and yet was not as strongly alkaline as concentrated caustic alkali.
The prior art, particularly U.S. Pat. Nos. 3,379,721; 3,591,509; and 3,663,445, discloses hard surface cleaners containing an alkaline material and water soluble sodium carboxymethylcellulose. However, it has been found that compositions containing an alkaline material, less alkaline than concentrated caustic alkali, and a water soluble form of a polysaccharide, such as sodium carboxymethylcelluose, are not good organic deposit removers. Although they may be capable of penetrating an organic deposit and do not present the same problems as do the caustic alkalis, such compositions dry rapidly and form a hard outer layer on the deposit, which makes washing the deposit off a utensil's surface difficult.
In accordance with this invention, hard surface cleaning compositions are provided which contain an alkaline material and a fibrous, water insoluble polymer capable of absorbing a large amount of water, so that when such a composition is applied to a deposit, the above mentioned hard outer layer is not formed and the deposit may be easily washed off.